Upon realizing the British company's ambitious plan of expanding their activities all over India and his glaring mistake, the Nawob aligned with the Danish to stop them but this resulted in defeat and his exit. With tactics later he won the confidence of the British and regained the throne for which he had to pay annually a large sum to the company. He ruled the state until his death in 1765.
After his death the British took complete control over Bengal and kept it till its independence 200 years later. Because of betrayal of his own country and people, Mir Jafer indirectly helped the British lay a strong foundation on the Indian soil. The British grabbed the Indian subcontinent one by one using tactics and military power. India was a big catch, the most important country in the British Empire. Mir Jafar is still known as Gaddar-e-Abrar, the betrayer of true faith.
Lesson: ''Wrong decision taken in haste or in a moment of aberration will have disastrous consequences.''